Before age 65 and after menopause, women who have normal bone density have a very low risk of fracture, shows a new study from the Women's Health Initiative (WHI).
The study got published online in Menopause
, the journal of The North American Menopause Society. That means these women don't need another bone mass density (BMD) test before age 65.
This study followed up 4,068 postmenopausal women ages 50 to 64 who had a BMD test, weren't taking hormones or calcium and vitamin D supplements in the trial, and didn't already have an osteoporotic fracture. Among the women who had no osteoporosis at the start of the study, it took from 12.8 years (for the youngest) to 7.6 years (for the oldest) for just 1% of them to sustain a vertebral fracture that caused problems or to sustain a hip fracture.
And it took from 11.5 years to 8.6 years for 3% of the women without osteoporosis at the start to sustain a major osteoporotic fracture, that is, a vertebral fracture that caused problems or a fracture of the hip, wrist, or top of the upper arm.
Those who did have osteoporosis at the outset had a high fracture risk, with 1% of them sustaining a problematic vertebral fracture or a hip fracture within just 3 years, and 3% of them sustaining a major osteoporotic fracture in just 2.5 years.
The decision to do a BMD test or repeat it after menopause is based on a judgment of a woman's risk of fracture, but research and debate on how to judge that risk are ongoing. Usually, a first test before age 65 is discouraged unless a woman has a medical condition where it or the treatment is associated with bone loss. What the risks are that can guide repeat testing have not been clear, and clinical practice varies widely.
"But the study just published online in the Society's journal provides evidence that the young postmenopausal women without osteoporosis on their BMD test, if they happened to have one before age 65, are not likely to need a repeat BMD test before 10 to 15 years have elapsed, barring significant health developments," says NAMS Executive Director and study coauthor Margery Gass, MD.